Autologous Blood Injection:
Tendonopathy (tendinopathy), also known as tendonitis and tendonosis, refers to painful conditions occurring in and around tendons in response to overuse. Commonly involved tendons are those in the elbow (lateral epicondyle), heel (Achilles), knee (patella), and shoulder (rotator cuff). Conservative therapies for patients with tendonopathies include rest, eccentric exercise, physiotherapy, analgesic therapy (e.g. non-steroidal anti-inflammatory drugs), use of orthotic devices, as well as local injection of steroids. Autologous blood injection has been employed when conservative therapies have failed. Blood taken from the patient by standard venesection is injected into the area around the damaged tendon. This approach is thought to promote healing by triggering stem cell recruitment, angiogenesis and fibroblast stimulation. A local anesthetic is usually used and ultrasound may provide guidance. Before injection, dry needling may be carried out. After the procedure, patients are instructed to avoid strenuous or excessive use of the tendon for several weeks (NICE, 2009).
Suresh and colleagues (2006) assessed if ultrasound guided autologous blood injection is an effective treatment for refractory medial epicondylitis. A total of 20 patients (13 men and 7 women) with symptom duration of 12 months underwent sonographic evaluation. Tendonosis was confirmed according to 3 sonographic criteria: (i) echo texture, (ii) interstitial tears and (iii) neovascularity. The tendon was then dry needled and autologous blood was injected. Patients were reviewed at 4 weeks and at 10 months. Visual analog scores (VAS) and modified Nirschl scores were assessed pre-procedure and post-procedure. There was significant reduction in VAS between pre-procedure and 10 months post-procedure when it had a median inter-quartile range (IQR) of 1.00 (1 to 1.75), range of 0 to 7. The median IQR Nirschl score, which at pre-procedure was 6.00 (5 to 7), range of 4 to 7, had decreased at 4 weeks to 4.00 (2.25 to 5), range of 2 to 7, and at 10 months to 1.00 (1 to 1.75), range of 0 to 7, revealing a significant decrease (z = 3.763, p < 0.001). The hypo-echoic change in the flexor tendon significantly decreased between pre-procedure, when there was a mean (SD) of 6.45 (1.47), and at 10 months, when it was 3.85 (2.37) (p < 0.001). Doppler ultrasound showed that neovascularity decreased between pre-procedure, when there was a mean (SD) of 6.10 (1.62), range of 4 to 9, and at 10 months, when it was 3.60 (2.56), range of 0 to 9 (p < 0.001). The authors concluded that the combined action of dry needling and autologous blood injection under ultrasound guidance appears to be an effective treatment for refractory medial epicondylitis as demonstrated by a significant decrease in VAS and a fall in the modified Nirschl scores.
Connell et al (2006) evaluated the effectiveness of autologous blood injection under sonographic guidance for the treatment of refractory lateral epicondylitis. A total of 35 patients (23 men and 12 women, mean age of 40.9 years, mean symptom duration of 13.8 months) underwent sonographic evaluation prior to dry needling the tendon and injection with autologous blood. Patients were reviewed, and measures of Nirschl and VAS were taken pre-procedure and post-procedure, at 4 weeks and 6 months. Following autologous blood injections, significant reductions were reported for Nirschl scores, which decreased from a median IQR pre-procedure score of 6 (6 to 7), to 4 (2 to 5) at 4 weeks (p < 0.001), and to 0 (0 to 1) at 6 months (p < 0.001). Similarly, significant reductions were reported for VAS scores from a median IQR pre-procedure score of 9 (8 to 10), to 6 (3 to 8) at 4 weeks (p < 0.001), and to 0 (0 to 1) at 6 months (p < 0.001). Sonography demonstrated a reduction in the total number of interstitial cleft formations and anechoic foci; a significant reduction in tendon thickness from a mean (SD) of 5.15 mm (0.79) at baseline to 4.82 mm (0.62) at 6 months post-procedure (p < 0.001) was observed. Hypoechoic change significantly reduced from a median IQR of 7 (6 to 7) at baseline to 2 (1 to 3) at 6 months post-procedure (p < 0.001). Neovascularity also significantly decreased from a median (IQR) of 6 (4 to 7) at baseline to 1 (0 to 3) at 6 months post-procedure (p < 0.001), although sonographic abnormality remained in many asymptomatic patients. The authors concluded that autologous blood injection is a primary technique for the treatment of lateral epicondylitis. Sonography can be used to guide injections and monitor changes to the common extensor origin.
In a prospective, cohort study, James et al (2007) evaluated the effectiveness of ultrasound-guided dry needling and autologous blood injection for the treatment of refractory patellar tendonosis. A total of 47 knees in 44 patients (40 men and 7 women, mean age of 34.5 years, age range of 17 to 54 years) underwent sonographic examination of the patellar tendon following referral with a clinical diagnosis of patellar tendonosis (mean symptom duration of 12.9 months). Ultrasound guided dry needling and injection of autologous blood into the site of patellar tendonosis was performed on two occasions 4 weeks apart. Pre-procedure and post-procedure Victorian Institute of Sport Assessment (VISA) scores were collected to assess patient response to treatment. Follow-up ultrasound examination was done in 21 patients (22 knees). Therapeutic intervention led to a significant improvement in VISA score: mean pre-procedure score of 39.8 (range of 8 to 72) versus mean post-procedure score of 74.3 (range of 29 to 100), p < 0.001; mean follow-up of 14.8 months (range of 6 to 22 months). Patients were able to return to their sporting interests. Follow-up sonographic assessment showed a reduction in overall tendon thickness and in the size of the area of tendonosis. A reduction was identified in interstitial tears within the tendon substance. Neovascularity did not reduce significantly or even increased. The authors concluded that dry needling and autologous blood injection under ultrasound guidance shows promise as a treatment for patients with patellar tendonosis.
In a single-blind, randomized, clinical study, Kazemi and colleagues (2010) compared local corticosteroid with autologous blood injections for the short-term treatment of lateral elbow tendinopathy. A total of 60 patients aged 27 to 64 years with a new episode of tennis elbow were recruited -- 30 patients were randomized to methylprednisolone and 30 to autologous blood group over 1 year. Severity of pain within last 24 hours; limb function; pain and strength in maximum grip; disabilities of the arm, shoulder, and hand quick questionnaire (Quick DASH) scores; modified Nirschl scores; and pressure pain threshold were evaluated before injection and at 4 and 8 weeks after injection. Data wer analyzed with the chi and t test. Within-group analyses showed better results for autologous blood (all p values < 0.001 except for grip strength, p = 0.005). In the corticosteroid group, differences in severity of pain (p = 0.008) and grip strength (p = 0.001) were significant. At 4 weeks, between-group analyses showed superiority of autologous blood for severity of pain (p = 0.001), pain in grip (p = 0.002), pressure pain threshold (p = 0.031), and Quick DASH questionnaire score (p = 0.004). There were no significant differences in modified Nirschl score, grip strength, and limb function. At 8 weeks, autologous blood was more effective in all the outcomes (all p values < 0.001). The authors concluded that autologous blood was more effective in short-term than the corticosteroid injection. The findings of this small, sinlge-blind study need to be validated by further investigation with larger number of subjects and longer follow-up.
The available evidence regarding the effectiveness of autologous blood injection for the treatment of tendonopathies is largely based on non-randomized studies. Their findings need to be validated by well-designed studies. Furthermore, available guidelines from the American College of Occupational and Environmental Medicine, National Institute for Health and Clinical Excellence (NICE), and Work Loss Data Institute do not support the use of autologous blood injection for tendonopathies.
The American College of Occupational and Environmental Medicine (2007) did not recommend autologous blood injection for managing patients with elbow disorders. The NICE's guideline on autologous blood injection for tendinopathy (2009) states that current evidence on the safety and effectiveness of autologous blood injection for tendinopathy is inadequate in quantity and quality. In addition, the NICE Committee notes that some of the published studies involved the use of dry needling prior to the injection of autologous blood, but it was not possible to differentiate between effects of these two components of the procedure. The Committee also states that future research should be in the context of randomized controlled studies that define chronicity of tendinopathy and describe any previous or adjunctive therapies (e.g., physiotherapy and dry needling) as well as the tendons treated. These studies should address the role of ultrasound guidance and include functional and quality of life outcomes with a minimum follow-up of 1 year. It is also interesting to note that the Work Loss Data Institute's guideline on the management of acute and chronic shoulder disorders (2007) did not mention the use of autologous blood injection as a means of therapy.
The Work Loss Data Institute's guideline on elbow (acute and chronic) (2011) stated that autologous blood injection is currently under study and is not specifically recommended.
Platelet-Rich Plasma Injection and Platelet Gel:
Besides autologous blood injection, other blood product injection therapies for the treatment of patients with tendonopathies include platelet-rich plasma (PRP) and bone marrow plasma.
In a pilot study, Mishra and Pavelko (2006) reported their findings on the treatment of chronic elbow tendonosis with PRP. A total of 140 patients were evaluated in this study. Subjects were initially given a standardized physical therapy protocol and various non-operative treatments. Twenty of these patients had significant persistent pain (mean of 82 of 100; range of 60 to 100 of 100 on VAS) for a mean of 15 months despite these interventions. All patients were considering surgery. This cohort of patients was then given either a single percutaneous injection of PRP (n = 15) or bupivacaine (n = 5). Eight weeks after the treatment, the PRP-injected patients noted a 60 % improvement in their VAS versus 16 % improvement in bupivacaine-treated patients (p = 0.001). Three of 5 of the control subjects (bupivacaine-treated) withdrew or sought other treatments after the 8-week period, preventing further direct analysis. Thus, only PRP-treated patients were available for continued evaluation. At 6 months, PRP-treated subjects noted a 81 % improvement in their VAS (p = 0.0001). At final follow-up (mean of 25.6 months; range of 12 to 38 months), the PRP-treated patients reported a 93 % reduction in pain compared with before the treatment (p < 0.0001). The authors concluded that treatment of patients with chronic elbow tendinosis with PRP reduced pain significantly. Moreover, they stated that further evaluation of this novel treatment is warranted.
In a randomized controlled trial (RCT), Peerbooms and associates (2010) examined the effectiveness of PRP compared with corticosteroid injections in patients with chronic lateral epicondylitis. A total of 100 patients with chronic lateral epicondylitis were randomly assigned in the PRP group (n = 51) or the corticosteroid group (n = 49). A central computer system carried out randomization and allocation to the trial group. Patients were randomized to receive either a corticosteroid injection or an autologous platelet concentrate injection through a peppering technique. The primary analysis included VAS and DASH Outcome Measure scores (DASH: Disabilities of the Arm, Shoulder, and Hand). Successful treatment was defined as more than a 25 % reduction in VAS or DASH score without a re-intervention after 1 year. The results showed that, according to the VAS, 24 of the 49 patients (49 %) in the corticosteroid group and 37 of the 51 patients (73 %) in the PRP group were successful, which was significantly different (p < 0.001). Furthermore, according to the DASH scores, 25 of the 49 patients (51 %) in the corticosteroid group and 37 of the 51 patients (73 %) in the PRP group were successful, which was also significantly different (p = 0.005). The corticosteroid group was better initially and then declined, whereas the PRP group progressively improved. The authors concluded that treatment of patients with chronic lateral epicondylitis with PRP reduces pain and significantly increases function, exceeding the effect of corticosteroid injection. They stated that future decisions for application of the PRP for lateral epicondylitis should be confirmed by further follow-up from this trial and should take into account possible costs and harms as well as benefits.
In a stratified, block-randomized, double-blind, placebo-controlled trial, de Vos and colleagues (2010) examined if a PRP injection would improve outcome in chronic mid-portion Achilles tendinopathy. A total of 54 randomized patients aged 18 to 70 years with chronic tendinopathy 2 to 7 cm above the Achilles tendon insertion were included in the study. Subjects received eccentric exercises (usual care) with either a PRP injection (PRP group) or saline injection (placebo group); randomization was stratified by activity level. The validated Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire, which evaluated pain score and activity level, was completed at baseline and 6, 12, and 24 weeks. The VISA-A score ranged from 0 to 100, with higher scores corresponding with less pain and increased activity. Treatment group effects were evaluated using general linear models on the basis of intention-to-treat. After randomization into the PRP group (n = 27) or placebo group (n = 27), there was complete follow-up of all patients. The mean VISA-A score improved significantly after 24 weeks in the PRP group by 21.7 points (95 % confidence interval [CI]: 13.0 to 30.5) and in the placebo group by 20.5 points (95 % CI: 11.6 to 29.4). The increase was not significantly different between both groups (adjusted between-group difference from baseline to 24 weeks, -0.9; 95 % CI: -12.4 to 10.6). This CI did not include the pre-defined relevant difference of 12 points in favor of PRP treatment. The authors concluded that among patients with chronic Achilles tendinopathy who were treated with eccentric exercises, a PRP injection compared with a saline injection did not result in greater improvement in pain and activity. They do not recommend this treatment for chronic mid-portion Achilles tendinopathy.
In a pilot study, Sampson et al (2010) evaluated the clinical effects of intra-articular PRP injections in a small group of patients with primary and secondary osteoarthritis (OA). A total of 14 patients with primary and secondary knee OA who met the study criteria received 3 PRP injections in the affected knee at approximately 4-week intervals. Outcome measures included the Brittberg-Peterson Visual Pain (VAS), Activities, and Expectations score and the Knee Injury and Osteoarthritis Outcome Scores at pre-injection visit at 2-, 5-, 11-, 18-, and 52-week follow-up visits. Musculoskeletal ultrasound was used to measure cartilage thickness. There were no adverse events reported. The study demonstrated significant and almost linear improvements in Knee Injury and Osteoarthritis Outcome Scores, including pain and symptom relief. Brittberg-Peterson VAS showed many improvements including reduced pain after knee movement and at rest. Cartilage assessment was limited because of the small sample size. The majority of the patients expressed a favorable outcome at 12 months after treatment. The authors concluded that the positive trends and safety profile demonstrated could potentially be used to inspire a larger, blinded, and randomized clinical trial to determine whether PRP is safe and effective for the treatment of knee OA.
Filardo et al (2011) examined the effects of intra-articular PRP injections for the treatment of degenerative cartilage lesions and osteoarthritis of the knee. Of the 91 patients evaluated in the previous 12-month follow-up study, 90 were available for the 2-year follow-up (24 patients presented a bilateral lesion, in a total of 114 knees treated). All of the patients presented a chronic knee degenerative condition and were treated with 3 intra-articular PRP injections. International Knee Documentation Committee (IKDC) and EQ-VAS scores were used for clinical evaluation. Complications, adverse events and patient satisfaction were also recorded. All of the evaluated parameters worsened at the 24-month follow-up: these parameters were at significantly lower levels with respect to the 12-month evaluation (the IKDC objective evaluation fell from 67 to 59 % of normal and nearly normal knees; the IKDC subjective score fell from 60 to 51), even if they remained higher than the basal level. Further analysis showed better results in younger patients (p = 0.0001) and lower degrees of cartilage degeneration (p < 0.0005). The median duration of the clinical improvement was 9 months. The authors concluded that these findings indicated that treatment with PRP injections can reduce pain and improve knee function and quality of life with short-term efficacy. They stated that further studies are needed to confirm these results and understand the mechanism of action, and to find other application modalities, with different platelet and autologous blood growth factors concentrations and injection timing, which provide better and more durable results.
Schepull et al (2011) noted that animal studies have shown that local application of PRP stimulates tendon repair. Preliminary results from a retrospective case series have shown faster return to sports. In a randomized controlled trial, these researchers hypothesized that autologous PRP stimulates healing of acute Achilles tendon ruptures. A total of 30 patients were recruited consecutively. During surgery, tantalum beads were implanted in the Achilles tendon proximal and distal to the rupture. Before skin suture, randomization was performed, and 16 patients were injected with 10 ml PRP (10 times higher platelet concentration than peripheral blood) whereas 14 were not. With 3-dimensional radiographs (roentgen stereophotogrammetric analysis; RSA), the distance between the beads was measured at 7, 19, and 52 weeks while the patient resisted different dorsal flexion moments over the ankle joint, thereby estimating tendon strain per load. An estimate of elasticity modulus was calculated using callus dimensions from computed tomography. At 1 year, functional outcome was evaluated, including the heel raise index and Achilles Tendon Total Rupture Score. The primary effect variables were elasticity modulus at 7 weeks and heel raise index at 1 year. The mechanical variables showed a large degree of variation between patients that could not be explained by measuring error. No significant group differences in elasticity modulus could be shown. There was no significant difference in heel raise index. The Achilles Tendon Total Rupture Score was lower in the PRP group, suggesting a detrimental effect. There was a correlation between the elasticity modulus at 7 and 19 weeks and the heel raise index at 52 weeks. The authors concluded that these findings suggested that PRP is not useful for treatment of Achilles tendon ruptures. The variation in elasticity modulus provides biologically relevant information, although it is unclear how early biomechanics is connected to late clinical results.
In a prospective, randomized, observer-blind controlled pilot study, Horstmann et al (2011) examined the effects of autologous platelet gel (APG), prepared from the buffy coat of a unit of autologous blood, after total knee arthroplasty (TKA) on blood loss, wound healing, pain, range of motion, and hospital stay. A total of 40 patients with only osteoarthritis of the knee were scheduled to have a TKA, and they were randomized into 2 groups. Patients in the treatment group were all treated with the application of APG after the prosthesis was implanted. Patients in the control group were treated with the same protocol but no APG was used. Pre-operative and post-operative hemoglobin levels showed no significant difference and allogeneic blood transfusions were not given in either group. Hematomas were significantly larger in the control group than in the platelet gel group (p = 0.03). The pain score at rest was higher in the control group on the 3rd day (p = 0.04). Wound healing disturbances were seen in 4 patients in the control group and in no patients in the APG group (n.s.). Range of motion of the knee was similar post-operatively. Hospital stay was 6.2 days in the APG and 7.5 days in the control group (n.s.). The authors noted that differences in favor of the use of APG were found, but these were subjective evaluations, marginal in effect, or did not reach statistical significance. The use of drains might have decreased the concentration of delivered platelets and may have diminished the effect. However, in this study, a statistically significant clinically important effect in favor of APG application was not found. They concluded that further studies with larger numbers of patients, and without the use of drains, are needed to investigate the possible benefits of APG in total knee arthroplasty.
Guadilla et al (2012) described a non-invasive arthroscopic procedure as an alternative to open surgery for avascular necrosis (AVN) of the hip. Patients with grade I or IIA AVN of the hip were treated by core decompression performed by drilling under fluoroscopic guidance. Liquid PRP was delivered through a trocar, saturating the necrotic area. In more severe conditions, the necrotic bone is decompressed and debrided, through a cortical window at the head-neck junction. A composite graft made of autologous bone and PRP was delivered by impactation through the core decompression track. Fibrin membranes were applied to enhance healing of the head-neck window and arthroscopic portals. Platelet-rich plasma was infiltrated in the central compartment. This arthroscopic approach aided in making diagnosis of the labrum and articular cartilage and permitted intra-operative treatment decisions. Visual control allowed the precise localization and treatment for the necrotic area allowing cartilage integrity to be preserved. The authors concluded that arthroscopic management of AVN of the femoral head is viable and has significant advantages. They stated that clinical studies should justify the theoretical additional benefits of this approach. An UpToDate review on "Osteonecrosis (avascular necrosis of bone)" (Jones, 2012) does not mention the use of PRP as a therapeutic option.
Sanchez et al (2012) evaluated the safety and symptomatic changes of intra-articular (IA) injections of PRP in patients with OA of the hip. A total of 40 patients affected by monolateral severe hip OA were included in the study. Each joint received 3 IA injections of PRP, which were administered once-weekly. The primary end point was meaningful pain relief, which was described as a reduction in pain intensity of at least 30 % from baseline levels as evaluated by the WOMAC subscale at 6-months post-treatment. The VAS and Harris hip score subscale for pain were used to verify the results. Secondary end points included changes in the level of disability of at least 30 % and the percentage of positive responders, namwly., the number of patients that achieved a greater than 30 % reduction in pain and disability. Statistically significant reductions in VAS, WOMAC and Harris hip subscores for pain and function were reported at 7 weeks and 6 months (p < 0.05). Twenty-three (57.5 %) patients reported a clinically relevant reduction of pain (45 %, range of 30 to 71 %) as assessed by the WOMAC subscale. Sixteen (40 %) of these patients were classified as excellent responders who showed an early pain reduction at 6 to 7 weeks, which was sustained at 6 months, and a parallel reduction of disability. Side effects were negligible and were limited to a sensation of heaviness in the injection site. The authors concluded that this preliminary non-controlled prospective study supported the safety, tolerability and efficacy of PRP injections for pain relief and improved function in a limited number of patients with OA of the hip. These findings need to be validated by prospective RCTs.
Bocanegra-Perez et al (2012) described the results of using PRP in the management of bisphosphonate-associated necrosis of the jaw. A total of 8 patients with a diagnosis of bisphosphonate-associated necrosis of the jaw were surgically treated for debridement and removal of necrotic bone, followed by application of autologous platelet concentrate enriched with growth factors and primary suture of the wound. Patients underwent periodic clinical and radiological follow-up examinations. All patients showed clinical improvement and oral lesions resolved 2 to 4 weeks following treatment. After an average 14-month follow-up period, patients remained asymptomatic. The authors concluded that although not conclusive, the combination of necrotic-bone curettage and PRP to treat refractory osteonecrosis of the jaw yielded promising results.
Bone Marrow Plasma Injection/Bone Marrow Derived Mesenchymal Stromal Cells Administration:
Moon and colleagues (2008) hypothesized that iliac bone marrow plasma injection after arthroscopic debridement of degenerative tissue will bring along biological cure. Thus, it will not only reduce pain but also improve function in patients with resistant elbow tendonitis. A total of 24 patients (26 elbows) with significant persistent pain for a mean of 15 months, despite of standard rehabilitation protocol and a variety of other non-surgical modalities were treated arthroscopically. These researchers examined the effects of autologous iliac bone marrow plasma injection following arthroscopic debridement. Bone marrow plasma is produced by centrifugation of iliac bone marrow blood at 1,800 rpm for 20 to 30 minutes. Patients were allowed full range of motion exercise after 2 to 3 days. Cytokine analyses for this injective material were done. Outcome was rated by post-operative sonography, VAS and Mayo elbow performance scores (MEPS) at 8 weeks and 6 months follow-up. All patients in this study reported improvement both in their VAS and MEPS; no complication was observed. Evidence of tendon healing was observed in post-operative sonographic examination. Predominant cytokines of this study were interleukin-12, interferon-gamma-inducible protein-10 and RANTES (regulated upon activation, normal T-cell expressed and secreted). The authors concluded the injection of iliac bone marrow plasma after arthroscopic debridement in severe elbow tendinosis demonstrated early recovery of daily activities and clear improvement.
In a phase I clinical trial, Duijvestein et al (2010) examined the safety and feasibility of autologous bone marrow derived mesenchymal stromal cells (MSCs) therapy in patients with refractory Crohn's disease. A total of 10 adult patients with refractory Crohn's disease (2 males and 8 females) underwent bone marrow aspiration under local anesthesia. Bone marrow MSCs were isolated and expanded ex vivo. Mesenchymal stromal cells were tested for phenotype and functionality in vitro. Overall, 9 patients received 2 doses of 1-2×10(6) cells/kg body weight, intravenously, 7 days apart. During follow-up, possible side effects and changes in patients' Crohn's disease activity index (CDAI) scores were monitored. Colonoscopies were performed at weeks 0 and 6, and mucosal inflammation was assessed by using the Crohn's disease endoscopic index of severity. Mesenchymal stromal cells isolated from patients with Crohn's disease showed similar morphology, phenotype and growth potential compared to MSCs from healthy donors. Importantly, immunomodulatory capacity was intact, as Crohn's disease MSCs significantly reduced peripheral blood mononuclear cell proliferation in vitro. Infusion of MSCs was without side effects, besides a mild allergic reaction probably due to the cryopreservant DMSO in 1 patient. Baseline median CDAI was 326 (224 to 378); 3 patients showed clinical response (CDAI decrease greater than or equal to 70 from baseline) 6 weeks post-treatment; conversely 3 patients required surgery due to disease worsening. The authors concluded that administration of autologous bone marrow derived MSCs appears safe and feasible in the treatment of refractory Crohn's disease. No serious adverse events were detected during bone marrow harvesting and administration. These preliminary findings of a phase I study need to be validated by well-designed studies.
Gupta and colleagues (2012) noted that OA is a degenerative disease of the connective tissue and progresses with age in the older population or develops in young athletes following sports-related injury. The articular cartilage is especially vulnerable to damage and has poor potential for regeneration because of the absence of vasculature within the tissue. Normal load-bearing capacity and biomechanical properties of thinning cartilage are severely compromised during the course of disease progression. Although surgical and pharmaceutical interventions are currently available for treating OA, restoration of normal cartilage function has been difficult to achieve. Since the tissue is composed primarily of chondrocytes distributed in a specialized extra-cellular matrix bed, bone marrow stromal cells (BMSCs), also known as bone marrow-derived "mesenchymal stem cells"or "mesenchymal stromal cells", with inherent chondrogenic differentiation potential appear to be ideally suited for therapeutic use in cartilage regeneration. Bone marrow stromal cells can be easily isolated and massively expanded in culture in an undifferentiated state for therapeutic use. Owing to their potential to modulate local micro-environment via anti-inflammatory and immunosuppressive functions, BMSCs have an additional advantage for allogeneic application. Moreover, by secreting various bioactive soluble factors, BMSCs can protect the cartilage from further tissue destruction and facilitate regeneration of the remaining progenitor cells in situ. The authors described the advances made during the last several years in BMSCs and their therapeutic potential for repairing cartilage damage in OA.
Rompe and colleagues (2008) stated that the management of Achilles tendinopathy is primarily conservative. Although many non-operative options are available, few have been tested under controlled conditions. Surgical intervention can be successful in refractory cases. However, surgery does not usually completely eliminate symptoms and complications are not rare. The authors stated that further studies are needed to discern the optimal non-operative and surgical management of mid-portion Achilles tendinopathy.
In a systematic review, Rabago et al (2009) appraised existing evidence for prolotherapy, polidocanol, autologous whole blood, and PRP injection therapies for lateral epicondylosis (LE). Results of 5 prospective case series and 4 controlled trials (3 prolotherapy, 2 polidocanol, 3 autologous whole blood and 1 PRP) suggested each of the 4 therapies is effective for LE. In follow-up periods ranging from 9 to 108 weeks, studies reported sustained, statistically significant (p < 0.05) improvement on VAS and disease specific questionnaires; relative effect sizes ranged from 51 % to 94 %; Cohen's d ranged from 0.68 to 6.68. Secondary outcomes also improved, including biomechanical elbow function assessment (polidocanol and prolotherapy), presence of abnormalities and increased vascularity on ultrasound (autologous whole blood and polidocanol). Subjects reported satisfaction with therapies on single-item assessments. All studies were limited by small sample size. The authors concluded that there is strong pilot-level evidence supporting the use of prolotherapy, polidocanol, autologous whole blood, and PRP injections in the treatment of LE. However, rigorous studies of sufficient sample size, assessing these injection therapies using validated clinical, radiological and biomechanical measures, and tissue injury/healing-responsive biomarkers, are needed to determine long-term safety and effectiveness, and whether these techniques can play a definitive role in the management of LE and other tendonopathies.
van Ark et al (2011) reviewed the different injection treatments, their rationales and the effectiveness of treating patellar tendinopathy. A computerized search of the Medline, Embase, CINAHL and Web of Knowledge databases was conducted on May 1, 2010 to identify studies on injection treatments for patellar tendinopathy. A total of 11 articles on 7 different injection treatments (dry needling, autologous blood, high-volume, PRP, sclerosis, steroids and aprotinin injections) were found: 4 RCTs, 1 non-RCT, 4 prospective cohort studies and 2 retrospective cohort studies. All studies reported positive results. The Delphi scores of the 4 RCTs ranged from 5 to 8 out of 9. Different and sometimes contradictory rationales were used for the injection treatments. The authors concluded that all 7 different injection treatments seem promising for treating patellar tendinopathy. Unlike the other injection treatments, steroid treatment often shows a relapse of symptoms in the long-term. They stated that results should be interpreted with caution as the number of studies is low, few high-quality studies have been conducted and the studies are hard to compare due to different methodology. They stated that more high-quality studies using the same cross-cultural reliable and valid outcome measure are needed, as well as further research into the pathophysiology.
In summary, there is currently insufficient evidence to support the use of various blood product injection therapies (e.g., autologous blood, PRP, bone marrow plasma) for the treatment of tendonopathies.